About our heatwave service
Our heatwave service includes:
- warnings of any severe or extreme heatwave within the next 4 days
- forecasts of heatwaves likely in the next 7 days.
Heatwave forecasts and warnings are generally issued from October until the end of March. Depending on conditions, the service may start earlier or run later.
Our heatwave service aligns with the National Heatwave Warning Framework (MS Word, 1.12 MB), an agreed approach to managing heatwaves across Australia.
Heatwave warnings
We issue a heatwave warning for severe or extreme heatwave conditions.
These warnings alert Australians that a heat hazard is forecast within the next 4 days. They help the community prepare for and lessen the impacts of a heatwave event.
What's in heatwave warnings
A heatwave warning includes:
- expected maximum and minimum temperatures
- when the heatwave will peak and/or ease
- a list of affected towns and communities within the warning area.
Action statements in heatwave warnings
The warnings include action statements that match the heatwave severity. These have been agreed with our partner health and emergency service agencies across Australia.
Our heatwave warnings complement heat health messages provided by state and territory agencies.
Issuing heatwave warnings
We issue a heatwave warning for your weather district when a severe or extreme heatwave is expected. To learn about heatwave classifications, see What is a heatwave?
How heatwave warnings are issued:
- in Warnings and alerts on this website
- on the BOM Weather app
- through our telephone audio warnings service.
Time issued:
- 3 pm local time for all states and territories except Western Australia.
- 2 pm local time in Western Australia.
Heatwave forecasts
Calculating the heatwave forecast
We calculate heatwaves using the observed and forecast maximum and minimum temperatures for the next 3 days. We compare this to:
- what would be considered hot for that location
- observed temperatures over the past 30 days.
The calculation allows for people's ability to adapt to heat. For example, the same temperature feels different to residents of Perth and Hobart. A 35° day will feel warmer to people who live in Hobart, as they are used to cooler temperatures.
This forecast method means that:
- after a relatively cool period, a sharp and sustained increase in temperature shows up in the heatwave forecast
- it takes higher temperatures to meet heatwave criteria at the end of summer, compared to earlier in the season.
Heatwave forecast map
A heatwave is calculated over 3 days. The 7-day forecast map combines:
- assessments of heatwaves in progress, and
- forecasts of heatwaves yet to start.
The map shows the final day of each 3-day assessment (today and tomorrow) and forecast (the following 5 days).
Service level specification for heatwave
This document describes our publicly available heatwave services. It also outlines the additional services we provide to support health and emergency management.